Issue #3465432 by pdureau, Grimreaper: [2.0.0-beta1] empty variants in pattern() Twig function

modules/ui_patterns_legacy/src/Template/TwigExtension.php

@@ -56,8 +56,14 @@ class TwigExtension extends AbstractExtension {
     $element = [
       '#type' => 'pattern',
       '#id' => $id,
-      '#variant' => $variant,
     ];
+
+    // Variant is a JSON-schema enum where empty string is not always allowed.
+    // Moreover, we don't allow empty variant.
+    if (!empty($variant)) {
+      $element['#variant'] = $variant;
+    }
+
     // We use the compact format, so it will be resolved by
     // RenderableConverter::resolveCompactFormat() before being converted to
     // the SDC format.

src/ComponentPluginManager.php

@@ -163,7 +163,6 @@ class ComponentPluginManager extends SdcPluginManager implements CategorizingPlu
     }
     return [
       'title' => 'Variant',
-      'type' => 'string',
       '$ref' => "ui-patterns://variant",
       'enum' => $enums,
       'meta:enum' => $meta_enums,

src/Plugin/UiPatterns/PropType/VariantPropType.php

@@ -14,10 +14,10 @@ use Drupal\ui_patterns\PropTypePluginBase;
 #[PropType(
   id: 'variant',
   label: new TranslatableMarkup('Variant'),
-  description: new TranslatableMarkup('Prop Type for component variants.'),
+  description: new TranslatableMarkup('Prop type for component variants.'),
   default_source: 'select',
-  schema: [],
-  priority: 10
+  schema: ['type' => ['string'], 'enum' => []],
+  priority: 1
 )]
 class VariantPropType extends PropTypePluginBase {